Until recently, digital display screens were limited to desktop and portable personal computers called laptops. The display screen orientation for these types of devices was generally fixed by the manufacturer. Desktop display screens were and are fixed with a mounting base and cannot be places on their short axis such that the screen is in portrait orientation. Laptops generally fall into the same limitation in that the screen axis is fixed because the keyboard and screen orientations are fixed.
The first PDA to appear in the market place did so in 1984 . This was a radical device and soon other manufacturers introduced their own PDAs. The Organiser II™ by PSION™ featured a hard keyboard with a small rectangular screen positioned above the keyboard. The Apple™ Newton™ was introduced to the market on Feb. 27, 1998 and featured a soft keyboard and a touch sensitive display screen. The PalmPilot™ introduced on Mar. 10, 1997 became the PDA for the masses. The PalmPilot™ featured a touch screen and a launchable soft keyboard and a reserved area of the display screen for character input via a stylus approximating stylized characters.
None of these PDAs would allow the user to reorient the display screen from portrait to landscape mode. Smart phones such as the Apple™ iPhone™ and PDAs such as the Apple™ iTouch™ were some of the first devices that allowed the user to change screen orientation between portrait and landscape.
Early tablets such as the Apple™ iPad™ allowed the user to lock the screen orientation by using the slide lock on the side of the device. Devices using the Android™ operating system give the users the ability to lock/unlock the screen orientation.
Display screens on laptop and other mobile devices such as tablet computers, PDAs and Cell Phones with soft or hard keyboards would rely on the physical orientation of the computing device to set the orientation of the content being displayed. If a user changes their physical body orientation to laying on their side and orients the display sideways so that landscape mode is preserved relative to the user, then the display screen and the computing device will generally reorient the display to portrait mode relative to gravity. This reorientation would make text on the display screen difficult to read.
The inventors recognize the advantages of having some way to lock the display orientation until the user performs some action to unlock the display screen orientation Apple™ mobile products such as iPad™, iTouch™ and other hand held device as well as Android™ mobile devices allow the user to disable auto-rotation of the display screen imagery by altering a setting in the systems setting menus.